Facebook Live is the biggest contributor to the pay-per-view theft. And it’s costing the fighters literally millions of dollars apiece.

It could be tens of millions apiece. For those fans who take to social media and profess to care about fighters and want to see them get paid more, know that you’re a hypocrite of the highest order because by watching an illegal stream, you’re taking money directly out of their pockets.

There are also at least three known unknowns in this bout:

• We know that we don’t know what kind of shape Chavez is actually in. He’s notorious for skipping workouts and not giving 100 percent effort. And even though everyone around him has been bragging about how hard he’s worked, that’s little more than hype. We won’t know the effort he put in until we see how he performs.

• We know that we don’t know how the fight’s 164.5-pound weight limit will impact Alvarez, who has never previously weighed higher than 155 in a bout. How will his speed, quickness and agility be impacted with an extra 10 pounds? Will his punch be as proportionally hard as it was at 155? Will his ability to take a punch be lessened since it’s coming from a man that much bigger? All we know in answer of these questions is that we don’t know.

• We also know that we don’t know the impact the passion of the crowd will have. Chavez’s father, Julio Cesar Chavez Sr., is an icon in Mexico, a Jordan-like figure who is revered by all. Alvarez is his linear successor, but a good number of fans will support the legend’s son. Will Alvarez be able to control his emotions and stick to the game plan? Will Chavez be able to use the crowd’s enthusiasm to mount a significant underdog’s challenge? We just don’t know.

Most interesting, though, are what the unknown unknowns might be.

In picking a winner in this fight, one must acknowledge that there are things that might happen or might influence the fight that we’re not thinking about now or which we may not be aware of even as the fight plays out.

And so it’s best to look at this from two vantage points: history and measurables.

History favors Alvarez. He’s been more consistent. He’s fought better opposition. He has, frankly, vastly outperformed Chavez throughout his career.

Measurables favor Chavez: He’s four inches taller and has a three-inch reach advantage. He can use his height, reach and jab to control the distance, keep Alvarez on the outside and away from his body, where he does brilliant and damaging work.

Alvarez is something of a slow starter, though he certainly wasn’t against James Kirkland. But for all his physical attributes, and they are many, he likes to take time to study his opponent.

He likes to gauge their speed and quickness. He likes to see how they move, how they react to his feints, how they put together their punches.

And, so, as Alvarez tries to figure out Chavez, if Chavez is firing a jab, dropping an occasional right hand behind it, and moves smartly out of danger, he’ll take early control of the fight.

Chavez’s consistency, though, is worrisome. He’s never shown he has it in him to concentrate and stick to a plan for three minutes a round, 12 rounds a fight.

He can’t afford to leave a lazy jab hanging out there, because if he does, Alvarez will quickly and brutally counter it. But if you look at Chavez’s previous fights, you’ll see that several times a fight, he flicks a jab and just leaves it there, as if he needs to take a quick breath before going on.

It’s a tough fight to pick, because there are so many variables, both known and unknown.

But when in doubt, go with the proven commodity. You know what you’re going to get with Alvarez. You’ll get a guy who is in shape, with a hard punch, a great chin and a determination to win that his opponent has never shown.

Chavez figures to have his moments, and it wouldn’t be a shock if he dropped Alvarez at one point.

This, though, will be the crowning moment of Alvarez’s career that the 2013 bout with Floyd Mayweather Jr. was not.